360 degree images, also known as immersive images or spherical images, are images where a view in every direction is recorded at the same time, shot using an omnidirectional camera or a collection of cameras. During photo viewing on normal flat displays, the viewer has control of the viewing direction and field of view. It can also be played on displays or projectors arranged in a cylinder or some part of a sphere. 360 degree photos are typically recorded using either a special rig of multiple cameras, or using a dedicated camera that contains multiple camera lenses embedded into the device, and filming overlapping angles simultaneously. Through a method known as photo stitching, this separate footage is merged into one spherical photographic piece, and the color and contrast of each shot is calibrated to be consistent with the others. This process is done either by the camera itself, or using specialized photo editing software that can analyze common visuals and audio to synchronize and link the different camera feeds together. Generally, the only area that cannot be viewed is the view toward the camera support.
360 degree images are typically formatted in an equirectangular projection. There have also been handheld dual lens cameras such as Ricoh Theta V, Samsung Gear 360, Garmin VIRB 360, and the Kogeto Dot 360—a panoramic camera lens accessory developed for the iPhone 4, 4S, and Samsung Galaxy Nexus.
360 degree images are typically viewed via personal computers, mobile devices such as smartphones, or dedicated head-mounted displays. Users may pan around the video by clicking and dragging. On smartphones, internal sensors such as gyroscopes may also be used to pan the video based on the orientation of the mobile device. Taking advantage of this behavior, stereoscope-style enclosures for smartphones (such as Google Cardboard viewers and the Samsung Gear VR) can be used to view 360 degree images in an immersive format similar to virtual reality. A smartphone display may be viewed through lenses contained within the enclosure, as opposed to virtual reality headsets that contain their own dedicated displays.